Standard, dry-blended haloapatite phosphor formulations are based on supplementing the major calcium and phosphorus-supplying ingredient, dicalcium phosphate, CaHPO4, (commonly referred to as Dical). This major ingredient comprises more than 65 weight percent of standard blends. Supplemental ingredients for Cool White and other similar color point haloapatite phosphors typically include CaCO3, CaF2, MnCO3, Sb2O3 and NH4Cl, listed in decreasing order of their weight fractions. These ingredients are blended in the correct proportions to provide a nearly stoichiometric compound, after firing, based on the generalized haloapatite phosphor composition (Ca(1−x−y)MnxSby)5(PO4)3(F(1−z−y)ClzOy), where 0<x<0.05, 0.004<y<0.01, and 0<z<0.1. For a haloapatite phosphor composition based on the Cool White color coordinates, the values of x, y and z are more particularly specified as 0.020<x<0.025, 0.0045<y<0.0075, and 0.04<z<0.08. Some of the ingredients volatilize on firing, therefore excess amounts of these more volatile ingredients must be added in the formulation to compensate for their firing losses. Of these, Sb2O3 and NH4Cl are the most volatile and must be added in much greater proportions than what is actually retained in the phosphor.